Make it easier to retrieve multiple results from an Acc run.

I have written some Accelerate programs in which I end up using multiple "run"s, often just for debugging or diagnostic purposes, for example, to print intermediate results in the computation.

The frustrating thing is that because it includes array level tuples and Let's, Accelerate compiles arbitrary _graphs_ of array operations. So of course it's already possible to extract many arrays of varying types from a single Accelerate run.

However, putting all the results into a big tuple of arrays can be inconvenient, especially with all the lifting and unlifting business.

Can anyone think of a way to make it easer to construct entire Accelerate computation graphs with multiple outputs? Perhaps the analogy is to the State monad vs. ST. It would be nice to be able to virtually "run" accelerate multiple times within a monad, but really only call a single run.